All of the INMEMO files may be stored in one account, which can be anything, but must be defined as an ersatz account called INMEMO:. In addition, if you are planning to use the help screen subsystem or the field menu subsystem, two additional ersatz accounts must be created: HLPMMO: and HLPMNU:. These can all be the same account. The only reason you may want to keep them separate is if you decide to customize either of the subsystems without changing the file names, putting them in separate accounts will prevent accidental overwriting of those files when restoring an update.
To define the ersatz accounts, use VUE to edit the SYS:ERSATZ.INI file and add the following lines:
INMEMO: = DSKx:[p,pn]
HLPMMO: = DSKx:[p,pn]
HLPMNU: = DSKx:[p,pn]
where DSKx:[p,pn] should be replaced by the actual disk and account numbers you decide to use.